In many applications, an operator of a remote surveillance system controls a remote image sensor via a communication link. Examples of such applications include traffic control, border control, search and rescue operations, land surveys, police surveillance, military applications, etc.
In general, a system for surveillance and remote tracking of objects (herein termed surveillance system) comprises a control unit at one location and a sensing unit at another location remote from the control unit, the control unit and sensing unit communicating over a communication link. The sensing unit, which comprises an image sensor, can be used for surveying a scene and transmitting sensing-data, which includes data that was acquired by the sensing unit or data generated by the sensing unit in relation to the acquired data (e.g. captured images, object-data characterizing identified objects in the captured images etc.) to the control unit. At the control unit the images can be displayed on a display for viewing by an operator. Furthermore, the sensing unit can be configured to locate and track a sighted object. The control unit provides to the sensing unit control-data, including for example, different types of commands, such as lock and track commands, zoom commands, centering commands, etc.
In some applications such as Terrain Dominance applications, it is desirable to capture large areas (e.g. of the ground) in a short time. One known solution involves using an imaging assembly suitably mounted onboard an aircraft, comprising a camera (CCD or CMOS) for capturing aerial images of ground terrain. The imaging assembly is configured with a motor for rotating an axis on which the camera is mounted, and for generating a sweeping back-and-forth motion shifting a field of view of the at least one camera. Multiple images of the ground terrain are captured and are synthetically combined into a single continuous image.
While this approach may provide imaging of a terrain area larger than the field of view (FOV) of the camera, it requires manufacturing a designated imaging assembly with a sweeping mechanism, capturing multiple images, and using fusion algorithms for generating the complete single image.